A common way of accessing the Internet is through a web browser. Web browsers can take a variety of forms. Some web browsers are installed on desktop computers, such as a personal computer running Microsoft Windows or Mac OS. Well known desktop web browsers include Google Chrome, Microsoft Internet Explorer and Mozilla Firefox. Other types of browsers are built into mobile applications that are downloaded from online stores and stored on mobile devices. For example, many popular mobile device applications use a browser engine that retrieves and renders data from the Internet.
Web browsers execute software that is referred to as a web application. One well known example of a web application is an Internet document or web page. In a typical web browsing session, a user will enter an address into a browser (e.g., http://www.yahoo.com) that is installed on a client device. The inputting of the address causes the browser to download a web application from a server associated with the address. The browser then executes the web application, which causes a web page to be displayed on the browser.
Web applications can be written in a variety of different scripts and languages. Most common languages are HTML, Javascript and CSS. With some scripts, such as Javascript, the script is executed at the client device. The execution of these languages can lead to the creation of dynamic and interactive applications. Example applications include movie players, image viewers, buttons, user interfaces, graphics, games and other features.
As web applications become increasingly complex, the execution of their associated scripts can require greater amounts of overhead and processing power. If the script is a client-side script such as Javascript, this can cause the performance of the client device and/or the browser to slow down. As a result, there are ongoing efforts to improve the performance of browsers and their ability to execute web applications.